1. Technical Field
The present invention relates to a separator for fuel cell and a fuel cell including the separator.
2. Background Art
In general, a fuel cell, for example, a polymer electrolyte fuel cell, is used in stack structure provided by stacking a plurality of power generation layers, each including an electrolyte membrane and a pair of electrodes (anode and cathode), via separators for separating a fuel gas and an oxidizing gas as reactive gases. Flow paths for fluids such as the reactive gases and a cooling medium (for example, cooling liquid), are formed inside the fuel cell.
One proposed separator for fuel cell has a corrugated cross-sectional shape including a plurality of first grooves concave to one surface and a plurality of second grooves concave to the other surface, which are arranged alternately. In this separator, the first grooves form flow paths for a first fluid (for example, cooling liquid) on one surface, whilst the second grooves form flow paths for a second fluid (for example, fuel gas) on the other surface. The fuel cell has manifolds for supplying and discharging the first fluid and the second fluid, which are formed to pass through the fuel cell in its stacking direction. The respective flow paths for the first fluid are connected with a first fluid supply manifold and with a first fluid discharge manifold. The respective flow paths for the second fluid are connected with a second fluid supply manifold and with a second fluid discharge manifold.
A known technique adopted for efficiently distributing a fluid over the whole area of the power generation layer forms flow paths for the fluid inside the fuel cell to have serpentine shape (hereinafter also called “serpentine flow paths”) (see, for example, JP 2003-242994A and JP 2009-170286A).